Single- and/or multi-charged gas ion beam treatment method for producing an anti-glare sapphire material

Abstract

A treatment method of a sapphire material, said method comprising bombardment of a surface of the sapphire material, said surface facing a medium different from the sapphire material, by a single- and/or multi-charged gas ion beam so as to produce an ion implanted layer in the sapphire material, wherein the ions are selected from ions of the elements from the list consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), boron (B), carbon (C), nitrogen (N), oxygen (O), fluorine (F), silicon (Si), phosphorus (P) and sulphur (S). Use of said method to obtain a capacitive touch panel having a high transmission in the visible range.

The invention claimed is: 
     
       1. A treatment method of a sapphire material to obtain an anti-glare treatment in the visible light range, said method comprising bombardment of a surface of the sapphire material by a single- and multi-charged gas ion beam so as to produce an ion implanted layer in the sapphire material, said surface having the ion implanted layer to be employed so as to interface with air, wherein:
 a dose of implanted single- and multi-charged gas ions per unit of surface area provided by the ion beam is chosen in a range between 10 12  ions/cm 2  and 10 18  ions/cm 2 ; and, 
 the bombardment being performed at a single acceleration voltage of the ion beam selected in a range between 5 kV and 1000 kV; 
 and, 
 wherein the ions of the single- and multi-charged gas ions are selected from ions of the elements from the list consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), boron (B), carbon (C), nitrogen (N), oxygen (O), fluorine (F), silicon (Si), phosphorus (P) and sulphur (S), 
 the dose of the implanted single- and multi-charged gas ions per unit of the surface area is chosen so as to obtain an atomic concentration of ions in the implanted layer such that a refractive index (nL) of the implanted layer is approximately equal to 
 (nA×nS) 1/2 , when the surface with the implanted layer air is interfacing with the air, 
 where nA is a refractive index of air in the visible light range and nS is a refractive index of sapphire material in the visible light range; 
 the acceleration voltage is chosen so as to obtain an ion implanted layer thickness (e) such that: 0.75 pλ/(4 nL)≤e≤1.25 pλ/(4 nL) 
 where:
 e is the ion implanted layer thickness at an ion implantation zone where the atomic concentration of the implanted single- and multi-charged gas ions is greater than or equal to 1% and wherein e is expressed in nanometer; 
 p is a non nil positive integer; 
 λ is an incident wavelength of the visible light range, wherein A is expressed in nanometer; and, 
 nL is the refractive index of the ion implanted layer, 
 
 wherein the treatment method obtains the anti-glare treatment at least for an incident wave having the incident wavelength (λ) in the visible light range while increasing transmittance in the visible light range. 
 
     
     
       2. The treatment method of  claim 1 , wherein the ion beam comprises 10% multi-charged ions or more than 10% multi-charged ions. 
     
     
       3. The treatment method of  claim 1 , wherein the acceleration voltage is chosen to obtain a value of the implanted layer thickness between 75p and 125p, expressed in nm, where (λ/4 nL)=100. 
     
     
       4. The treatment method of  claim 1 , wherein the dose of implanted single- and multi-charged gas ions per unit of surface area is chosen to obtain a value of the atomic concentration of the ions in the implanted layer of greater or equal to 5% and equal or less than 20%. 
     
     
       5. The treatment method of  claim 1 , wherein the dose of the implanted single- and multi-charged gas ions per unit of surface area is chosen in a range between 10 16  ions/cm 2  and 10 18  ions/cm 2 . 
     
     
       6. The treatment method of  claim 1 , wherein the acceleration voltage is chosen in a range between 10 kV and 100 kV. 
     
     
       7. The treatment method of  claim 1  wherein the dose of the implanted single- and multi-charged gas ions and the acceleration voltage are further chosen using data gathered in a step prior to bombardment by the single- and multi-charged gas ion beam of the sapphire material to be treated, wherein:
 said step consists of choosing an experimental ion beam having one type of single- and multi-charged ions of the elements from the list consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), boron (B), carbon (C), nitrogen (N), oxygen (O), fluorine (F), silicon (Si), phosphorus (P) and sulphur (S), performing a plurality of experiments with an experimental sapphire material similar to the sapphire material to be treated by bombarding the experimental sapphire material using said experimental ion beam and varying an experimental dose of the implanted single- and multi-charged gas ions per unit of surface area provided by the experimental ion beam and an experimental acceleration voltage of the experimental ion beam until determining a desired implanted single- and multi-charged gas ion dose per unit of surface area range and a desired acceleration voltage range so as to produce the anti-glare treatment in the visible light range; 
 wherein the gas ion beam uses the one type of single- and multi-charged ions chosen for the experimental ion beam, wherein the dose of the implanted single- and multi-charged gas ions per unit of the surface area is chosen to be within the desired implanted single- and multi-charged gas ion dose per unit of surface area range and the acceleration voltage is chosen to be within the desired acceleration voltage range. 
 
     
     
       8. The treatment method of  claim 1  wherein the dose of the implanted single- and multi-charged gas ions and the acceleration voltage are further chosen by:
 choosing the ion beam to be one type of the single- and multi-charged ions of the elements from the list consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), boron (B), carbon (C), nitrogen (N), oxygen (O), fluorine (F), silicon (Si), phosphorus (P) and sulphur (S); 
 choosing the dose of the implanted single- and multi-charged gas ions per unit of surface area of the ion beam and the acceleration voltage value of the ion beam according to a calculation based on an ion implantation profile according to an implantation depth for the implanted single- and multi-charged ions of the ion beam, where said ion implantation profile has been previously calculated or determined for a plurality of experimental acceleration voltages so as to produce the implanted ion layer to obtain a desired anti-glare treatment in the visible light range, so as to obtain a value of the atomic concentration of the ions in the implanted layer of greater or equal to 5% and equal or less than 20%. 
 
     
     
       9. The treatment method of  claim 1  wherein the dose of the implanted single- and multi-charged gas ions and the acceleration voltage are further chosen by:
 choosing the ion beam to be one type of single- and multi-charged ions of the elements from the list consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), boron (B), carbon (C), nitrogen (N), oxygen (O), fluorine (F), silicon (Si), phosphorus (P) and sulphur (S); 
 choosing the dose of the single- and multi-charged gas ions per unit of surface area and the acceleration voltage according to following equation:
   0.02≤ DC   2 /( TΔn )≤2; wherein:
 
 
 D is a single- and multi-charged gas ion dose per unit of surface area value to be chosen, expressed in 10 16  ions/cm 2 ; 
 C=M/15, where M is the atomic mass of the chosen one type of single and multi-charged ions, 
 T is an acceleration voltage to be chosen, expressed in kV; 
 Δn is the refractive index difference between the refractive index, nS in the visible light range, of the sapphire material to be treated and the refractive index, the nA in the visible light range of the air interfacing with the surface. 
 
     
     
       10. The treatment method of  claim 9  wherein DC 2 /(TΔn) is greater or equal to 0.1 and/or equal or less than 1.